Fluid turbine retarder



Aug. 15, 1967 w s. NAGEL FLUID TURBINE RETARDER 7 Sheets-Sheet 1Original Filed Aug. 10, 1964 1967 w. s. NAGEL I 3,335,823

FLUID TURBINE RETARDER 7 Sheets-Sheet 2 Original Filed Aug. 10, 1964INVENTOR. m/lLL/AM J? NA GEL.

Aug. 15, 1967 w. s. NAGEL FLUID TURBINE RETARDER 7 Sheets-Sheet 5Original Filed Aug. 10, 1964 I N VEN TOR WILL/AM JJVA L Aug. 15, 1967 w.s. NAGEL 3,335,823

FLUID TURBINE RETARDER Original Filed Aug. 10, 1964 '7 Sheets-Sheet 4INVENTOR.

W/LL/AM 5. NAGZL rATTOR/VL' YJ Aug. 15, 1967 w. s. NAGEL FLUID TURBINERETARDER -7 Sheets-Sheet 5 Original Filed Aug, 10, 1964 IN VENTOR.

Mil //7 M N46Z BY & ,ww MTTO/P/VE Y5 FLUID TURBINE RETARDER OriginalFiled Aug. 10, 1964 7 Sheets-Sheet INVENTOR. Z" WILL/AM 5. NAGEL Aug.15, 1967 w. s. NAGEL FLUID TURBINE RETARDER 7 Sheets-Sheet 7 OriginalFiled Aug 10, 1964 mz me 493 M2 /72 INVENTOR. W/LZ/AM A/A GL- UnitedStates Patent 3,335,823 FLUID TURBINE RETARDER Wiliiam S. Nagel,Bloomfield Township, Mich, assiguor to Eaton Yale & Towne Inc, acorporation of Ohio Original application Aug. 10, 1964-, Ser. No.391,827, now

Patent No. 3,291,268, dated Dec. 13, 1966. Divided and this applicationFeb. 16, 1966, Ser. No. 544,049

12 Claims. (Cl. 188-90) This application is a division of my copendingapplication, Ser. No. 391,827, filed Aug. 10, 1964, now Patent No.3,291,268, which in turn is a continuation-in-part of my applicationSer. No. 306,131, now abandoned.

This invention relates to speed retarder units for motor vehicles andrelates particularly to one intended for connection ahead of at least aportion of the transmission gears of the vehicle and utilizing thevehicle cooling fluid for its energy absorption medium.

The usefulness of an effective and efficient energyabsorbing unit formotor vehicle use supplementary to the braking system thereof has beenunderstood for a number of years and a variety of devices has beenutilized for this purpose. Briefly, however, it may be said that speedretarder units are normally turbine devices connectible to the drivewheels of an automotive vehicle, usually by being connectible to someportion of the drive line of the vehicle, and are provided with meansfor absorbing energy from the rotor of said turbine and dissipating sameas heat to the atmosphere.

More specifically, it has been understood for many years that the usesolely of brakes for controlling the speed of a vehicle in hilly ormountainous terrain often overheats the linings and drums of said brakesand same will at best last for only a short period. This problem haslong been commonly met in passenger car travel by connecting the enginein a substantially unpowered condition to the drive wheels of thevehicle in order to use the drag of the engine for assisting the brakesand preventing excessive vehicle speed.

Extending this same concept to heavier vehicles, such as trucks,retarder units of a number of different designs have been offered to themarket. Most of these retarder units have been installed in the driveline of the vehicle, usually between the transmission and thedifferential gearing of the vehicle and in series with a suitablyshortened drive shaft. In addition, at least one retarder unit has beendesigned for placement at the forward end of the vehicle transmission asan integral part thereof and operating in conjunction with the inputgears of the transmission.

These units, insofar as I am aware, operate satisfactorily but theystill present certain problems which it is the purpose of the presentinvention to correct. For example, where a unit is placed anywherebetween the transmission and the drive wheels of the vehicle, it willrun relatively slowly when the vehicle is going at a relatively slowspeed. Since the etfective braking torque developed by a turbine-typeretarder increases as an exponential function of its speed, a retarderunit that is large enough for low-speed operation is excessive forhighspeed operation, or conversely, a retarder unit that is correctlydesigned for higher-speed operation is totally inadequate when operatedat low speeds. Thus, means should be provided for driving the retarderat a suitably high speed through a high ratio when the vehicle is goingslowly but which will drive same at approximately the same speed througha low ratio when the vehicle is going rapidly.

To meet this problem, it has been proposed to place the retarder unitahead of the transmission gearing, or at least ahead of a portion of thetransmission gearing, whereby the transmission gears themselves providethe 3,335,823 Patented Aug. 15, 1967 desired ratio above mentioned.Thus, at high speeds, with the transmission in direct drive, theretarder unit will be driven at a speed sufficient for its effectiveoperation and at low vehicle speeds the transmission may be placed inits low-gear condition and the retarder unit is still driven at asufficiently high speed to be effective.

However, in all of these units, the problem of withdrawing the absorbedenergy from the unit has required special consideration. Where the unitshave been placed behind the transmission, they have normally utilizedoil as the energy-absorbing medium and this has required a suitable heatexchanger for cooling the oil and usually a pump for insuringcirculation of the oil between the retarder unit and the heat exchanger.All of this has added expense to the apparatus as well as inconveniencein the installation of same.

In the unit built as an integral part of, but at the forward end of, atransmission, the transmission lubricant is available forenergy-absorbing purposes but this still requires means for cooling saidlubricant and, hence, the necessity for a special heat exchanger, pumpand appropriate connections is still present.

It has been suggested to avoid the necessity for a special heatexchanger and pump by connecting the retarder to the engine coolantsystem whereby to use the engine radiator and coolant pump fordissipating the heat developed in the retarder. However, this is notfeasible for obvious reasons where the retarder unit is built into thetransmission as an integral part thereof. Where the retarder unit is inthe drive line of the vehicle, the connection to the engine radiator ismechanically feasible but the use of engine coolant, which is usuallywater, requires that the retarder unit be made of rustresistingmaterials and in view of the relatively large size required of theretarder where it is placed in the drive line as above pointed out, thecost of same becomes excessive.

Accordingly, the objects of the invention include:

(1) To provide a retarder device for automotive use adaptable for usewith the coolant system of the vehicle engine and connectible to thevehicle drive system at a point therein ahead of at least one pair ofthe transmission ratio gears.

(2) To provide a vehicle retarder, as aforesaid, which is sufficientlysmall as to be capable without excessive cost of being manufactured ofrelatively expensive, waterresistant, materials whereby to enable it tobe connected to the vehicle engine cooling system.

(3) To provide a vehicle retarder system, as aforesaid, wherein theretarder can be connected as an accessory after the manufacture of thevehicle has otherwise been completed.

(4) To provide a vehicle retarder system, as aforesaid, wherein theadditional mechanism required is small and inexpensive, may be appliedto an otherwise completed vehicle quickly, easily and by mechanics ofonly ordinary training and skill and wherein the maintenance required tokeep said retarder system in good operating condition is minimal.

(5) To provide a retarder system, as aforesaid, wherein the enginecooling radiator may function as the heat exchanger for dissipatingunwanted energy from the retarder during the period in which the serviceof said radiator to the engine is not needed.

(6) To provide a retarder unit which can be rendered operative orinoperative as desired with only simple controls.

Other objects and purposes of the invention will be apparent to personsacquainted with apparatus of this general type upon reading thefollowing disclosure and upon inspection of the accompanying drawings.

In the drawings:

FIGURE 1 is a schematic plan view of an automotive vehicle showing themanner of installing the retarder unit embodying the invention.

FIGURE 2 is an elevation of said retarder unit as seen from the sidethereof which is forward with respect to the direction of vehicleoperation.

FIGURE 3 is a section taken on the line III--III of FIGURE 2.

FIGURE 4 is a section taken on the line IVIV of FIGURE 2.

FIGURE 5 is a view of the stator side of the apparatus as viewedsomewhat along the line VV of FIGURE 3 and looking in the direction ofthe arrows, and with all but a fragment of the rotor structure removed.

FIGURE 6 is a section taken on the line VIVI of FIGURE 5.

FIGURE 7 is a modification of the control mechanism.

FIGURE 8 is an enlarged fragmentary central cross sectional view of amodified form of a retarder unit embodying the invention substantiallyas taken along the line VIII-VIII of FIGURE 11.

FIGURE 9 is an enlarged sectional View taken on the line IX--D( ofFIGURE 8.

FIGURE 10 is an enlarged sectional view taken on the line X-X of FIGURE8.

FIGURE 11 is an elevation of said modified retarder unit as seen fromthe side thereof which is forward with respect to the direction ofvehicle operation.

FIGURE 12 is a fragmentary sectional view taken on the line XIIXII ofFIGURE 8.

FIGURE 13 is a fragmentary sectional view taken on the line XIII-XIII ofFIGURE 8.

FIGURE 14 is a fragment of FIGURE 8 showing a modification thereof.

FIGURE 15 is a fragment of FIGURE 8 showing another modificationthereof.

FIGURE 16 is an enlarged sectional view taken on the line XVI-XVI ofFIGURE 11.

FIGURE 17 is a sectional view taken on the line XV II- XVII of FIGURE16.

FIGURE 18 is a schematic diagram of a control system operable with theembodiment of FIGURE 16.

FIGURE 19 is a diagrammatic view of a modified control system operablewith the retarder unit of FIGURE 8.

FIGURE 20 is an enlarged fragmentary partially broken sectional viewsubstantially as taken on the line XX- XX of FIGURE 19.

FIGURE 21 is a central cross-sectional view substantially as taken onthe line XXI-XXI of FIGURE 20.

FIGURE 22 is an enlarged fragmentary central crosssectional vie-wsubstantially as taken on the line XXII XXII of FIGURE 19.

Detailed description In the following description, certain terms will beused solely for convenience in description and will have no limitingsignificance. For example, the terms upwardly and downwardly will referto directions taken with respect to the normal position of use of theretarder as shown in FIGURES 2 and 11. The terms rightwardly andleftwardly will be used with reference to particular drawings. The termsinwardly and outwardly will refer to directions toward and away from thegeometric center of the apparatus. Said terms will also includederivatives of the words above specifically mentioned as well as otherwords of generally similar import.

Looking first at FIGURE 1, there is shown an automotive vehicle of anytype having a frame I, an engine 2 driving through a clutch 3 andtransmission 4 to a propeller shaft 5 and thence through a difierential6 to drive wheels indicated generally at 7 and 8. A heat exchanger, orradiator, 9 is indicated as connected conventionally at the forward endof the vehicle and connected from its lower end by a conduit 11 to thewater pump 12 which discharges into the lower end of the engine waterjacket in the usual manner. A conduit 13 connects the upper end of theengine water jacket to the upper end of the radiator 9.

All of the foregoing is conventional and has been illustrated solely toassist in understanding the invention.

Turning now to the retarder unit itself, the same is indicated generallyat 14 in FIGURE 1 and, as more fully illustrated in FIGURES 2 through 6,inclusive, consists of a housing 16 having suitable means, as a flange17, for mounting said unit by machine screws 18 to the side of thetransmission 4. Said housing 16 has a rotor chamber 24 (FIGURE 3)therewithin and includes a rotor-bearing support portion 19 arranged forsupporting rotor bearings 21 and 22. Said bearings are of anyconventional type and are supported in any convenient manner which willbe readily apparent to those skilled in the art and therefore needs nodetailing. A cover 23 closes the chamber 24.

A rotor 26 is supported by said bearings 21 and 22 and carriesperipherally formed thereon suitable teeth 27 arranged for drivingengagement with a drive gear 28. Said drive gear is carried by rollers29 on an inner bearing race member 31 which is received into a drivechamber 32 in the housing 16. The inner bearing race member is held inplace by a pin 33 and held against rotation by a suitable screw 34. Thegear 28 meshes with any conveniently available gear 36 within thetransmission housing, such as the head gear at the forward end of thetransmission countershaft or a gear in the power take-off train. Whileit is preferable to select a connection to the transmission to have asmany as possible of the transmission ratios between the gear 28 and theoutput of the transmission, at least some of the advantages of theinvention can be obtained with less ratios between the gear 28 and theoutput of the transmission providing only that the gear 28 is positionedahead of at least one of such ratios.

Extending from the portion of the rotor 26 which carries the teeth 27 isin this embodiment a portion 37 of reduced diameter which extends pastan oil seal 38 and a water seal 39 and terminates in a splined portion41. The turbine rotor 42 is fastened thereto and consists of a centerplate 43 and blade means 44. Said blade means are formed in anyconvenient and conventional manner which in this embodiment consists ofan annular troughlike element 46 of semi-circular cross section andcontaining a plurality of partitions of which two are shown at 47 and 48(FIGURE 6). These partitions are in this embodiment arranged angularlyat about 45 degrees with respect to the general plane of the trough-likeelement 46 and are related to the direction of rotation of the rotor asindicated by the arrow in FIGURE 6. The stator 51 of the retarder unitcomprises an annular trough-like element 52 which is similar to thetrough-like element 46, is arranged in opposition thereto and issuitably fastened, such as by welding, to the housing 16.

Said stator has an annular inlet manifold 53 arranged adjacent theretowhich manifold communicates through the stator by a plurality ofpassageways formed therein of which one is indicated at 54. As shown inFIGURES 5 and 6, said passageways flair both radially andcircumferentially at each of their ends in order to obtain the mostefficient fluid flow into the turbine structure in accordance with wellknown and accepted turbine-design techniques. A conduit 55 is formed inthe housing 16 and connects with the interior of the annular manifold53. Fluid entering the turbine enters through the conduit 55, thencethrough the several nozzles 54 (FIGURES 5 and 6) and against the flowaligners or partitions above mentioned. Braking fluid then dischargesfrom the rotor means 42 at the outer periphery thereof into a chamber 56which communicates with an outlet pipe 57.

In this device, the liquid braking fluid relationships of the rotor 42and stator are such that they will act somewhat as a pump whereby theliquid braking fluid is drawn into the system from the chamber 53through the inlet passageways 54 and into the rotor 42. The partitions47 and 48 align and direct the flow of said fluid thereby causing sameto absorb energy with maximum efficiency from the mechanical meansdriving said rotor and said liquid is then expelled through the outlet57.

Turning now to the remainder of this system, said outlet 57 is connectedwith a passageway which may be any convenient conduit 58 either flexibleor rigid which is in turn connected to the inlet side of the radiator 9,such as by being connected to the high temperature engine conduit 13.The low temperature side of the radiator, such as a portion of theoutlet of the pump 12 is connected by a conduit 59 to the inlet 55 ofthe retarder unit 14 and the circuit is complete.

The unit may be rendered operative or inoperative by any of severalpossible means. For example, one such control may be obtained by anyconventional means (not shown) for connecting and disconnecting the gear36 from the remainder of the transmission.

Alternatively, where said gear 36 is a constantly operating part of thetransmission, as where it is a head gear on the transmissioncountershaft, then the rotor of the retarder 14 may operate continuouslybut the fluid flow therethrough may be interrupted. Referring to FIGURE7, control means hereinafter described are shown as interposed into thesupply line 59 and the discharge line 58. In this control means, thesupply line 59 is shown with a valve 271 placed therein. The dischargeline 53 from said retarder has flow-interrupting means located therein,which latter means may be a valve but is here shown as a trap 277. Asource S of air under pressure connects through a line 274 and a valve275 to a chamber 276 of fixed but relatively small size. The chamber 276is then connected by a line 278 through a valve 273 to the line 59 at apoint between the valve 271 and the retarder unit 14. Mechanical meansgenerally indicated at 279 are preferably provided between the valves271, 273 and 275 to facilitate their simultaneous operation, valves 271and 275 being opened while valve 273 is closed, and vice versa. Thevolumetric capacity of the chamber 276 is related to that of theretarder unit 14 and the conduits connected thereto, as well as to thepressure available from the source S, in such a manner that the quantityof air admitted into said chamber 276 will be sufiicient when the valves271 and 275 are closed and the valve 273 is open to expand into theretarder 14- and drive the liquid therein to a point past the trap 277.

Operation The operation of the apparatus has been somewhat indicatedabove but will be reviewed for the purpose of insuring completeunderstanding of the invention.

The gear 36 is assumed to be continuously operating so that the retarderunit is rendered operative or inoperative at the will of the operator bysuitable manual control (not shown) of the valves 271, 273 and 275. Theapparatus is placed in condition for operation by opening the valve 275and closing the valve 273. With the mechanical valve operating systemabove described, this will also open the valve 271 so that if the engineis operating it will permit fluid to enter into the retarder 14. This,however, is immaterial at this point. The opening of the valve 275 andclosing of the valve 273 permits air from the source S to enter into thechamber 276 and fill same to a predetermined pressure. The control 279is now reversed and the valve 275 is closed, the valve 273 is opened andthe valve 271 is closed. This permits air from the chamber 276 to enterinto the retarder housing 16 and drive any liquid therein out of saidunit and past the trap 277. The rotor within said housing will now actonly against the air therein and will accordingly run without loadthereon and will impart no appreciable retarding torque into the runningsystem of the vehicle. Thus, the vehicle may be operated in a normalmanner.

However, when it is desired to render the retarder operative, thevalve-control 279 will be manually moved to reverse the valves 271, 273and 275. This will permit coolant liquid from the engine radiator totravel by the line 59 through the valve 271 and into the retarder unit14, thence back through the line 58 to the radiator 9. The airpreviously within the retarder unit 14 will be carried by the coolantliquid as desired, but most conveniently to the radiator where it willbleed out by any suitable means (not shown) associated with theradiator. In the meantime, with the opening of the valve 275, a newcharge of air under pressure is introduced into the chamber .276 inpreparation for the next cycle of operation.

Introduction of liquid into the retarder 14 will permit the rotortherein to act against said liquid and impart energy thereto. Thus,liquid is drawn at a low-energy level from the return line 59, isaccelerated by the rotor of the retarder 14 thereby drawing energy fromthe mechanical means driving said rotor and is impelled at a high-energylevel into the line 58. Said high-energy level is manifested primarilyas heat energy which is dissipated by the radiator 9.

It will be observed that the retarder will be used only when the engineis in, or substantially in, a loafing condition so that the use made ofthe radiator 9 by the retarder will be at such periods in the operationof the vehicle that only a small heat-dissipating action of the radiatorwill be required by the engine. Further, since the excess energydeveloped by the vehicle running downhill under gravity will be roughlyequal to the energy rejected by the engine in driving the vehicleuphill, the capacity of the radiator 9, designed to dissipateengine-generated heat, will be suflicient to dissipate the mechanicalenergy converted by the retarder unit into heat energy.

Further, it will be recognized that by placing the retarder ahead of oneor more sets of ratio gears in the transmission, when the vehicle isrunning at a fairly high speed and thereby the transmission is in ahigh-speed gear ratio the retarder will operate at the desired highspeed but when the vehicle is operating at a low speed, the transmissioncan be shifted into a low-speed ratio and the retarder will therebystill be caused to operate at the desired high speed with respect to thedrive wheels of the vehicle. Thus, regardless of the speed of thevehicle, the retarder will operate at a high rotational speed, such as2,500 r.p.m. at all times and it will accordingly operate at a highlevel of efiiciency and effectiveness. Thus, it is possible for theretarder to be made of a small size regardless of the size of thevehicle with which it is to operate. For example, a retarder having arotor of approximately six inches in diameter will be capable underordinary conditions and by suitable gear ratio selection of developingapproximately 200 horsepower for braking purposes regardless of thespeed of the vehicle and this is ample for most purposes.

By making it possible for the retarder to be small, it now becomeseconomically feasible to make it of waterresistant materials, eventhough such materials are relatively expensive, and thus it becomesfeasible to use the engine coolant as the energy absorbing anddissipating medium for the retarder. This in turn means that the onlyapparatus which will need to be applied to a vehicle toprovide thedesired retarding function is the retarder unit 14 itself, therelatively inexpensive conduits 58 and 59 and the retarder controls.This further reduces the cost of both the unit itself and the cost ofinstalling same.

If the control over the operation of the retarder is exercised byconnecting and disconnecting of the gear 36, the same operatingcharacteristics and advantages above described will be equallyobtainable, subject only to such inconvenience and/or expense as mayexist incident to connecting and disconnecting the gear 36 from theremainder of the transmission.

7 Modification of FIGURES 8-18 Turning now to FIGURES 8 through 13,there is shown means for connecting and disconnecting the rotor of aretarder 14a to the gear 72 which may now be assumed to be continuouslyrotating whenever the output shaft of the transmission is rotatingv Insuch case the valving shown in FIGURE 7 will be omitted and the lines 58and 59, as shown in FIGURE 1, connected directly between the appropriateports of the retarder unit 14a. and the cooling system of the vehicleengine.

In FIGURE 8 a part of the housing structure and the rotor portions arethe same as those shown in connection with FIGURES 1 through 7 and areidentified by numerals corresponding to those used in connectiontherewith but further identified by the sufiix a. No further descriptionof these elements will be needed.

In this modification there is provided a spindle 71 whose rightward end37a (FIGURE 8) corresponds to the portion 37 appearing in FIGURE 3. Saidspindle is supported within and by the gear 72 further describedhereinafter, in part by the bushing 22a and in part by the clutchmechanism hereinafter described. Arranged onto said spindle by thesplines 73 is a clutch fitting 74, said fitting comprising an innershort, cylindrical flange 76 which is splined to the splines 73 of thespindle, an outer long, also cylindrical, flange 77 and a radiallypositioned web 78 connecting said two flanges. A pressure equalizingring 79 is arranged between the two flanges 7-6 and 77 and closelyadjacent the web 78. A plurality, such as three, openings are providedtherein of which one appears at 81 for the reception of a plurality ofpins, such as the pin 82, said pin-s extending through said web 78 andbeing joined for simultaneous operation by a spider 83. Said spider andpins carried thereby are continuously urged leftwardly, as appearing inFIGURE 8, by a spring 84 within the axial bore 86 in the leftward end ofthe spindle 71. Any suitable mechanical means, such as a rotatable cam87 mounted on and for rotation with a shaft 88 is provided for urgingsaid spider 83 against the spring 84 and thereby urging said pinsrightwardly. Any convenient means, partly indicated at 90 (FIGURE 11)are provided for enabling theoperator to rotate the shaft 88.

A clutch ring 89 (FIGURE 8) is arranged on and for movement with therightward face of the pressure equalizing ring 79. Said clutch ring 89is preferably made of highfriction material, such as any of the manyplastic-and-fiber materials made for this purpose.

An annular first energizing unit 91 is arranged next rightwardly of theclutch ring 89 and comprises a radial flange 92 arranged to bear againstthe clutch ring 89 and r an axial cylindrical flange 93 which extendsrightwardly from the flange 92. The first energizing ring: 91 isarranged for free rotative movement with respect to the clutch fitting74 and the friction ring 89. A relatively light first clutch spring 94is wrapped around the spindle 71 and has one end 94a (FIGURE 9) anchoredin the cylindrical flange 93 whereby rotation of the energizing ring 91will initiate rotation of the clutch spring 94, the hand of said springbeing such that the drag provided by subsequent connection to theturbine rotor 46a will effect a tightening of said spring 94 onto thespindle 71.

Telescoped over the spring 94 is a second energizing unit 96 whoserightward end is provided with an inwardly directed flange 97 and whoseleftward end is provided with an outwardly directed flange 98. Therightward end of the spring 94 is anchored into the flange 97, as in amanner similar to end 94a (FIGURE 9), for rotation therewith. A secondspring 99, preferably substantially larger than the first spring 94, isarranged within the annular chamber 101 defined between the flange 77and the central portion of the energizing unit 96. Suitable means, asthe step construction 102 (FIGURE are provided for effecting positiveengagement by the flange 98 against the end 99a of the spring 99 uponrotation of said second Lit) energizing unit 96. Similar means areprovided for positively relating the rightward end of said spring 99with a spring retainer 103. Said spring retainer 103 encircles saidenergizing unit 96 and is connected in any convenient manner, such as bya dowel pin 104, for rotation with the gear 72.

Turning now to further consideration of said gear 72, the same isprovided with a central opening which telescopes over the flange 77 andis supported at its leftward end in a bearing 21a and in its other endin a suitable bearing structure 196, whose inner rightward end embracesthe outer and leftward surfaces of the bushing 22a.

The operation of the apparatus will be readily understood. When the cam87 is in such position as to permit the spider 83 to move leftwardlyunder the urging of the spring 84, the clutch ring 89 does not engagethe first energizing unit 91 as the parts are in nondrivingrelationship. Under these conditions, rotation of the gear 36 causesrotation of the gear 72 and this carries with it rotatingly the springretainer 103, the spring 99, the second energizing unit 96, the spring94 and the first energizing unit 91. The clutch fitting 74, clutch ring89, pressure equalizing ring 79 and the par-ts associated therewith arerotatively fixed with respect to the spindle 71 and these parts do notrotate due to the lack of a driving torque.

Under these conditions a vehicle on which the retarder is used may beoperated in a normal manner and the retarder will be inoperative eventhough coolant liquid flows from the radiator 9 of the vehicle throughthe retarder 14 and then back to said radiator. However, when theoperator of the vehicle desires to use the retarder as shown in FIGURES8-13, he effects by any convenient means, as through the lever 90,rotation of the shaft 88 which rotates the cam 87 to urge spider 83rightwardly against the spring 84. This effects rightward movement ofthe pressure-equalizing ring 79 and the clutch ring 89 to causeengagement thereof against the first energizing unit 91 for urgingrotation thereof. The rotational torque thus applied to the firstenergizing unit 91 may be very light and in fact needs to be onlysuflicient to cause the leftward end of the relatively light spring 94to engage the spindle 71. Since said spring is rotating relativelyrapidly as above pointed out, and the spindle 71 is substantiallynonrotating, a wide speed differential will exist therebetween so thateven a relatively light touching of the leftward end of said spring 94against said spindle will effect an extremely rapid wrapping andengagement of said spindle by said spring 94. The resistance to rotationof said spindle by its connection to the rotor 46a will restrain itagainst the rotation imposed onto it by its relationship with the gear72 and thereby effect a relative rotational torque therebetween. Thiseffects an expansion of the second spring 99 outwardly against thecylindrical flange 77 and effects an extremely tight engagement betweensaid spring 99 and said flange 77.

This effects a driving relationship from gear 72 through pin 104 andspring retainer 103 through the spring 99 and flange 77 to the clutchfitting 74 and thence to the spindle 71. This will effect a satisfactorydriving for certain uses, usually light uses, as pointed out in themodification referred to hereinafter. However, in the preferredembodiment of FIGURES 8-13, the flange 77 is very closely fitted intothe central opening 105 and is preferably slotted as indicated at 111(FIGURE 13) whereby upon expansion of the spring 99, the flange 77 isexpanded firmly against the gear 72 to provide a solid and directconnection from the gear 72 through the clutch 74 to the spindle '71.Thus, a relatively light force momentarily imposed onto the shaft 88will act as above set forth to create a connection between the gear 72and the spindle 71 of sufficient torque-carrying capacity to carry theconsiderable load developed by the rotor 46a. Thus, the retarder unit14a is rendered operative and its operation proceeds in the same manneras above described in connection with FIGURES 1 to 7, inclusive.

When it is desired to declutch or uncouple, the shaft 88 is rotated tomove spider 83 leftwardly away from spring 84, thus allowingpressure-equalizing ring 79 and clutch ring 89 to move out of engagementwith first energizing ring 91. The torsional characteristic of spring 94is such that disengagement of clutch ring 89 from first energizing ring91 allows spring 94 to unwind and thus become frictionally released fromspindle 71.

Referring to FIGURE 14, there is shown a fragmentary view of themodification suggested above wherein the flange 77 is spaced from theinner surface of the gear 72 whereby the entire drive will be throughthe dowel pin 104. In this modification the parts are all identical butthe corresponding parts above described in connection with FIGURE 8 arereferred to by the same numerals with the letter b added thereto. Thiswill indicate that the parts are the same as above described inconnection with FIGURES 8-13 excepting that, as shown in FIG- URE 14,the slots 111 are omitted and an annular space indicated at 112 isprovided. Thus, reliance is placed solely upon the pin 104, and suchadditional counterparts thereof as may be provided ,for effecting drivebetween the spring retainer 183 and the gear 72 which will be ample incertain circumstances and which will be advantageous where, ifpreferred, the gear 72 does not telescope flange 77 but instead is, forexample, located entirely to the rig-ht of the spring retainer 103 asfragmentarily illustrated in FIGURE wherein corresponding parts arenumbered as in FIGURE 8 but with the letter 0 added thereto.

FIGURES 16, 17 and 18 disclose a modified control system for theretarder of FIGURES 8 through 13. The shaft 88 (FIGURE 11) is supportedat the outward end thereof by a suitable bearing block 131 and has fixedthereto for rotation therewith a pinion gear 132 whereby a rotation ofthe lever 90 causes a corresponding rotation of the pinion gear 132. Agear case 133 fixed on the retarder housing 16 houses the pinion 132 andbearing block 131 and supports for reciprocation within a cylindricalcentral opening 137 (FIGURE 16) a preferably cylindrical rack 136. Thepinion 132 drivingly engages the rack 136. In FIGURE 16 the pinion 132is shown dottedly out of its normal position to indicate the engagementof said pinion 132 with the rack 136.

Suitable wiper means 138 in the outer (leftward in FIGURE 16) end of thegear housing 133 wipe the outer end of the rack 136 in a conventionalmanner to prevent entrance of foreign particles into the central opening137. The rack 136 has a preferably coaxial central opening 139 throughthe inner (rightward as seen in FIGURE 16) end thereof.

The outer end of the opening 139 comprises a portion 141 of reduceddiameter communicating through a suitable threaded opening 142, fitting143, line 144 (FIGURE 18) and thence through the cover 146 (FIGURE 8)with the turbine chamber 147 defined thereby. Hence, an increase inpressure in the turbine chamber 147 will appear at the outer portion 141of the central opening 139 (FIG- URE 16).

Said portion 141 communicates with a midportion 148 of slightlyincreased diameter which houses a piston 149 having a sealing ring 151thereon and an axially inwardly extending piston rod 152 connectedthereto, The rod 152 extends out of the inward end of the centralopening 139 in the rack 136. A slide block 153 closes the outward end ofthe central opening 139 and radially supports the piston rod 152 foraxial sliding movement therethrough. A spring 140 lies within thecentral opening 139 and bears at one end upon the inner face of thepiston 149 and the other end thereof upon the facing surface of theslide block 153 to bias the piston 149 outwardly (leftwardly in FIGURE16). The piston rod 152 has an extension rod 154 pivotally secured tothe inward end thereof which at its inner end is pivotally secured at156 to the operating knob 157 (FIGURE 17) of a butterfly valve 158 whichselectively opens and closes the inlet conduit 55 of the retarder uponproper operation of the knob 157. Suitable stop means, here the pins 161and 162, control the limits of motion of the valve 158 by striking theadjacent edge surface of the extension arm 154. A suitable boot 163 ofany convenient type prevents the inner end of the piston rod 152 frombringing foreign material in the central opening 139.

The butterfly 158 normally (FIGURE 17) lies in a position slightlybehind its fully closed position and is thus at an angle of less than tothe longitudinal axis of the conduit 55. Due at least to the limit pin161, the butterfly 158 cannot narrow this angle and can move only in theopposite direction through its closed position and further ahead to anopen position, the angle of said open position with said longitudinalaxis being determined by the limit pin 162. Also in the normal (FIGURE16) position of the apparatus, the piston 149 is fully retracted withinthe rack 136' and the rack 136 is fully retracted, in the oppositedirection, within the gear case 133. It will thus be seen that motion ofeither the rack 136 or piston 149 from their normal (FIGURE 16)positions will result in forces in opposed directions through theextension arm 154 and butterfly 158. In this manner, the motion of thepiston rod 152 may be used to counteract the motion of the rack 136 tocontrol the volume input of fluid to the retarder and to thereby controlthe amount and manner of application of deceleration torque to thevehicle by the retarder as detailed immediately hereinbelow.

Upon .a suitable rotation of the shaft 88 by means of the lever 90(FIGURE 11), the cam 87 on said shaft is rotated to move the spider 86(FIGURE 8) and hence the ring 89 into frictional contact with the means92 whereby to cause the rotor shaft 71 to become coupled to the gear 72and hence to the drive train of the vehicle for retarding same. Suchrotation of the shaft 88 rotates the pinion gear 132 which in turn movesthe rack 136 outwardly from its normal (FIGURE 16) position for movingthe butterfly 158 clockwise from its normal slightly open position ofFIGURE 16 through a fully closed position and to a fully open position.

The initial rotation of the shaft 88 causes the retarder to couple tothe vehicle drive train, as. discussed hereinabove, and also rotates thebutterfly 158 to its closed position to minimize fluid flow to theretarder turbine and minimize the pressure in the turbine chamber 147.At this point, then, the decelerative torque of the retarder is smalland the connection of the retarder into the vehicle drive train takesplace with a minimium of shock even though it occurs with the vehicleoperating at a high speed. Thereafter, the power absorption of theretarder may be progressively increased, as set forth below, with thedecelerative torque thus created likewise progressively increasing butremaining at all times under the constant control of the operator andwithout danger of sudden changes.

Further rotation of the shaft 88 causes further translation of the rack136 to continue the clockwise (FIGURE 16) rotation of the butterfly 158from its closed position. Hence, more fluid will be allowed into theinput conduit 55 whereby turbine torque will increase and the retarderwill tend to decelerate the vehicle more strongly. However, the pressurein the turbine chamber 147 will be increased by the increase in fluidflow and by an amount also dependent on the speed of the gear 72 and,hence, on ve- -hicle speed, and said increase in pressure in the chamber147 is applied through the line 144 to the outward end of the piston 149moving same inwardly whereby the extension rod 154 tends to move thebutterfly 158 in a closing or counterclockwise direction thusneutralizing, to an extent dependent on the speed of the vehicle, theinward movement of the rack 136. Thus, the line 144 and piston 149comprise a negative feedback mechanism for reducing the effect ofchanges in vehicle speed and fluid pressure and temperature on thetorque output of the retarder. As the speed of the vehicle decreases andthe gear 72 turns less rapidly a retarder without this control woulddecrease its output torque. However, in the instant retarder thepressure will drop in the chamber 147 and the spring 140 will thus urgethe piston 149' leftwardly (FIGURE 16) whereby to open the butterfly 158further to increase the flow of fluid through the input conduit 55 andthereby increase the efliciency of the retarder unit. Further, theoperator may vary the decelerative torque at will by repositioning therack 136 and hence butterfly 158 by rotation of the lever 90.

The embodiment of the invention hereabove described contemplatescontrolling the flow or fluid into the retarder unit through the inputconduit 55. It has been found that throttling the outlet conduit 57 isunsatisfactory from at least two points of view. In the first place, thechange in pressure within the turbine chamber 147 caused by throttlingthe output conduit 57 is small compared with the back pressure createdby the turbine exhaust on the inner periphery of the turbine and hencethe operating conditions of the turbine are changed insufficiently bythrottling of the output conduit 57 to significantly change the outputtorque thereof. In the second place, throttling of the exhaust conduit57 lessens the exhaust flow from the turbine and hence lessens theamount of heat carried away from the turbine thereby possibly causingthe turbine to overheat whereas the throttled inlet control systemdescribed hereinabove does not affect heat transfer from the turbine.

Modification of FIGURES 19-22 FIGURES 19, 20 and 21 disclose a furthermodified control system 171 for a retarder substantially similar, forexample, to that of FIGURES 8 through 13. Parts of the apparatusdiscussed below which are similar to portions of the retarder andcontrol system described above will be indicated by the same referencenumerals thereas with the suflix d added thereto. The modified controlsystem 171 (FIGURE 19) includes a control cylinder 172 mounted uponrightward (in FIGURE 19) end portion 187 of the retarder 14d adjacentthe inlet conduit 55d. A conduit 144d connects the control cylinder 172with the turbine chamber enclosed by the cover 146d for supplying fluid,and in the embodiment shown, liquid from within said turbine chamberthereto. A fluid pressure regulating valve 176 includes a manuallyoperable handle 177 and is preferably mounted by any convenient meanssuch as the mounting member 178 on the vehicle within reach of thevehicle operator. One side of the regulating valve 175 connects to aline 179 fed by a source S of fluid, preferably air, under pressure. Aline 181 connects the other side of the valve 176 to the controlcylinder 172. Thus, manipulation of the handle 177 of the regulatingvalve 176 will vary the air pressure supplied by the source S to thecontrol cylinder 172.

The control valve 172 (FIGURE 20) includes a cylindrical housing 182which is rigidly aflixed by means of a strap 183 and screws, one ofwhich is indicated at 18 3-, to a buttress 186 on the periphery of theend portion 187. A piston 191 is reciprocable Within the central opening192 of the cylindrical housing 182. An elongated piston rod 193 ispreferably integral with the piston 191) and extends rightwardlytherefrom. A passage 194 communicates with the rightward end of thecentral opening 192 and is defined by an annular flange 196 whichextends radially inwardly from the rightward end of the housing 182. Thepiston rod 193 snugly but slidably extends through the passage 194.

The piston rod 193 defines an annular liquid chamber 198 in the centralopening 192 between the annular flange 196 and the piston head 191. AnO-ring 197 is seated within a suitable annular groove in the passage 194for bearing against the periphery of the piston rod 193 to seal therightward end of the annular chamber 198. The periphery of the pistonhead 191 is annularly grooved for receiving an O-ring 199 which bears onthe wall of the central opening 192 for sealing the leftwardeud of thechamber 193. In the particular embodiment shown, the piston 191 has aleftwardly opening central recess 201. A coil spring 202 substantiallycoaxially surrounds the piston rod 193 and is compressible between thepiston head 191 and the annular flange 196 for urging the piston 191leftwa-rdly in the cylindrical housing 192. A cap 2133 is threaded intothe leftward end of the cylindrical housing 182 and defines with thepiston 191 an air chamber 2114. A fitting 206 connects the line 181through the cap 203 to the air chamber 204. A fitting 207 connects theline 14411 through the peripheral wall of the cylindrical housing 182 tothe liquid chamber 198 adjacent the rightward end thereof. The centralopening 192 is provided with a leftwardly facing step 2119 between thefitting 207 and the cap 203 for limiting rightward movement of thepiston 191.

A butterfly valve plate 158d is disposed within the leftward or inletend of inlet conduit d for opening and closing said conduit. The plate158d is affixed to a rotatable shaft 211 which extends substantiallydiametrically through the inlet conduit 55d substantially toward thecentral axis of the control cylinder 172 adjacent the rightward end(FIGURE 20) of said cylinder. A cylindrical block 212 affixed to the endof the shaft 211 lies adjacent said central axis of the control cylinder172.

A preferably integral and coaxial stub 213 extends rightwardly from thepiston rod 193 and is reduced in diameter with respect thereto. The endof the stub 213 pivotally supports the leftward end of an extension rod154a. A pin 216 is affixed eccentrically to the end face of the block212 and pivotally engages the intermediate portion of the extension rod154a.

With the piston 191 in its leftwardmost position of FIG- URES 20 and 21,the pin 216 is located above the central axis of the block 212 so thatrightward movement of the piston 193 will result in counter-clockwisemovement (as viewed in FIGURE 21) of the butterfly plate 158d. Aneccentrically located stop pin 162d axially projects from the radialface of the block 212. When the valve 158d is closed as indicated in thedrawings, said stop pin 162d bears upon the upper surface of therightward end of the extension rod 154d to prevent clockwise (as seen inFIG- URE 21) movement of the plate 158d from its closed position.Counter-clockwise rotation of the plate 158d past its fully openedposition is prevented by contact between the shoulder 209 and the piston191.

A flexible boot 163d telescopes over an axial flange 217 on therightward end of the housing 182. The boot 163d is fixed to the flange217 by any convenient means, here a conventional retaining ring 218. Theboot 163d extends rightwardly from the housing 182 and loosely surroundsthe stub 213 and extension shaft 154d. The block 212 extends through asideward opening 219 in the boot 163d. The boot 163d protects theabove-mentioned linkage between the piston rod 193 and shaft 211 againstdirt.

The control system 171 hereinabove described may, if desired, be usedwith the retarder 14 0f FIGURES 813, the shaft 88 and cam 87 of theretarder 14 being retained for energizing the spider 83 and ring 89 toclutch the retarder 14 to the vehicle transmission. However, the controlsystem 171 (FIGURE 19) may be used with clutch controlling means otherthan the aforementioned shaft 83 and cam 87 of FIGURE 8. Morespecifically, the control system 171 is particularly adapted to use witha fluid, preferably air controlled, clutch actuating system 226'. Theclutch actuating system 220 includes an air actuated displacement devicewhich in the present embodiment of the invention comprises an aircylinder 226 (FIGURE 22) integral with the portion 137 of the retarder14d. The inner end of a piston 227 bears on the spider 83d and isreciprocable in the cylinder 226 for actuating said spider to clutch theretarder 14d to the transmission. An air feed line 221 connects throughthe end plate 228 of the portion 187 to the outer end of the cylinder226 to supply air under pressure thereto for moving said piston andspider inwardly against the spring 84d. The air line 221 also connectsto a pressure valve 222. The pressure valve 222 is fed by the source Sof air under pressure through a line 223. The line 181 connects to thepressure valve 222 by a fitting 224, the pressure valve 222 allowingflow therethrough to the line 221 and hence to the portion 187 uponappearance of air pressure in the line 181. Conversely, the pressurevalve 222 shuts off air pressure from the source S to the retarderportion 18-7 when the regulating valve 176 is turned off and thepressure of the line 181 falls below its normal operating range. Theclutching of the retarder 146a to the vehicle transmission is thusautomatically accomplished by manipulation of the regulating valve 176controlling the liquid input to the retarder.

Since the control system 171 will often be more conveniently used withactuating system 220, the operation of the control system 171 will bedescribed in terms thereof. The butterfly plate 158d is normally held inits closed position by the leftward urging of the piston 191 by thespring 202. When the control system 171 is used with the clutchactuating system 220, initial opening of the regulating valve 176 isturned off and the pressure of the clutching the retarder 14d to thevehicle transmission. The pressure in line 181 required to initiatecompression of the spring 202 by the piston 191 is preferably greaterthan that required to actuate the pressure valve 222. Thus, the retarder14d will be clutched to the vehicle transmission before the initialopening of the butterfly 158d occurs. Further opening of the regulatorvalve 176 sufficiently pressurizes the air chamber 204 via line 181 asto cause an initial rightward displacement of the piston 191. As aresult, the butterfly plate 158d pivots (in a counter-clockwisedirection as seen in FIGURE 20) to allow liquid to flow at a restrictedrate into the retarder 14d through the inlet conduit 55d. Since theretarder 14d is now clutched to the vehicle transmission, said retarder14d retards the vehicle. Thus, a gradual opening of the regulator valve176 results in a smooth increase from zero of the retarding torqueexerted by the retarder 14d.

Were the butterfly plate 158d controlled only by the regulator valve176, liquid pressure in the turbine chamber and in the liquid chamber198 would tend to increase with increasing vehicle speed therebyproducing excessive retarding torque at high engine speeds and/ orinsuflicient torque at low speeds. The present control system overcomesthis tendency by reducing torque at high speeds while maintaining usefultorque output at low speeds so that torque output is substantially ofthe same magnitude at high and low speeds. This result is achieved inthe present system by using the aforementioned tendency for pressure inthe turbine chamber to increase with an increase in speeds. Morespecifically, the line 144d maintains liquid in the annular liquidchamber 198 of the control cylinder 172 at the same pressure as theliquid in the turbine chamber. The pressurized liquid in the liquidchamber 198 acts with the spring 202 to resist rightward movement of thepiston 191 urged by the air pressure in the air chamber 204 and, hence,opening of the butterfly plate 158d. Thus, at high engine speeds, thepiston 191 will open the butterfly plate by a lesser amount than wouldnormally be the case in the presence of a given air pressure in the airchamber 204. As a result, less liquid will be admitted to the retarderpast the butterfly plate 158d at high engine speeds, the resultingretarding torque of the retarder 14d thereby being reduced.

At low engine speeds, the liquid in the turbine chamber and, the liquidchamber 198 is relatively lOW and the air pressure on the leftward endof the piston 191 is chiefly opposed by the spring 202. The butterflyplate 158d may therefore be opened more by a given air pressure in theair chamber 204 for admitting more liquid to the turbine chamber. Thistends to bolster retarder torque output at low speeds so the retardertorque output will be substantially similar at high and low enginespeeds.

Increased opening of the regulating valve 176 increases the air pressurein the air chamber 204 so that the piston 191 opens the butterfly plate158d and so increases retarding torque. The rightward limit of thepiston 191 corresponds to the fully opened position of the butterflyplate 158d.

While particular retarder designs have been described somewhat in detailherein for the purpose of making a complete disclosure of the preferredembodiments, it will be recognized that such specific retarder designs,while useful and believed to be novel by themselves, are onlyrepresentative of many designs which can be used within the scope of thegeneral system herein described and the broader aspects of the inventionwill be recognized as embracing other forms of retarder units asdesired.

In addition, there are other individual features of the apparatus hereinspecifically disclosed which are set forth for convenience ofdescription only and will be recognized as subject to variations asneeded to meet the desires of the individual designer or the individualinstallation.

Accordingly, such variations will be recognized as within the scope ofthe hereinafter appended claims, excepting as said claim specificallyrequire otherwise.

What is claimed is:

1. In a turbine retarder for a vehicle having drive wheels andtransmission means driving same, the combination comprising:

a rotatable main shaft;

a turbine for retarding the rotation of said main shaft and including arotor rotatable with said main shaft; driving means rotatable from saidtransmission means; first resilient means rotatably driven at one endthereof in response to rotation of said driving means; torque transfermeans and means for rotatably driving same at one end thereof inresponse to rotation of the other end of said first resilient means;

clutch means fixed for rotation with said main shaft and having a sleeveportion thereof in telescoped relation with, and located closelyadjacent, said first resilient means; and

disconnectible engaging means actuatable to cooperate with the other endof said torque transfer means for connecting same to said clutch means;

whereby actuation of said disconnectible engaging means connects saidother end of said torque transfer means to said clutch means whichapplies a torque between the ends of said torque transfer means, andsaid torque transfer means in resisting the rotation imposed upon it bysaid first resilient means torsionally distorts said first resilientmeans sufficiently to cause same to contact said sleeve portion of saidclutch means to effect a driving connection through said clutch meansbetween said driving means and said main shaft whereby said turbineretards the rotation of said driving means.

2. The device defined in claim 1 wherein said firs-t resilient meanscomprises a cylindrical, spiral spring.

3. The device defined in claim 1 wherein said driving means ispositioned radially outwardly of said first resilient means.

4. The device defined in claim 1 wherein said engaging means includes:

an energizing ring surrounding said main shaft and rotatable withrespect thereto and driveably connected to said other end of said torquetransfer means;

a clutch ring axially movably mounted on said clutch means forfrictionally engaging said energizing ring whereby to connect same tosaid main shaft;

spider means actuatable to axially move said clutch ring; and

means for actuation of said spider means.

5. The device defined in claim 1 wherein said clutch means comprises anannular ring having a circumferen- 15 outer flange, both of said flangesextending axially to one side of said annular ring;

said inner flange surrounding said main shaft and being fixed thereto;

said inner and outer flanges defining an annular chamber for containingparts of said engaging means; and

said outer flange closely surrounding said first resilient means, being'closely surrounded by said driving means, and being expandable bydistortion of said first resilient means to frictionally engage saiddriving means.

6. The device defined in claim 1 wherein said sleeve portion of saidclutch means is positioned radially inwardly of, and spaced radiallyfrom, the inner wall of said driving means whereby the sole drivingconnection between said driving means and said clutch is through saidfirst resilient means.

7. The device defined in claim 1 wherein said torque transfer meanscomprises a second resilient means closely surrounding said main shaftand which is of less strength than said first resilient means wherebysaid torque exerted upon said second resilient means causes distortionthereof whereby said second resilient means frictionally engages saidmain shaft.

8. The device of claim 7 wherein said second resilient means comprises acylindrical, spiral spring.

9. The device defined in claim 1 wherein said first resilient means iscoaxial with and telescoped over said torque transfer means.

10. The device defined in claim 9 wherein said driving means is coaxialwith and telescoped over said first resilient means.

11. The device defined in claim 1 wherein said d-riving means has acentral opening and the sleeve portion of said clutch means istelescoped closely therewithin but in normally rotatable relationshipwith respect thereto, whereby said torisional distortion of said firstresilient means expands said sleeve portion and thereby effects adriving contact between said sleeve and said driving means.

12. The device defined in claim 11 wherein said sleeve is axiallyslotted.

References Cited UNITED STATES PATENTS 1,576,996 3/1926 Radclifle192--l2 MILTON BUCHLER, Primary Examiner.

G. E. HALVOSA, Assistant Examiner.

1. IN A TURBINE RETARDER FOR A VEHICLE HAVING DRIVE WHEELS ANDTRANSMISSION MEANS DRIVING SAME, THE COMBINATION COMPRISING: A ROTATABLEMAIN SHAFT; A TURBINE FOR RETARDING THE ROTATION OF SAID MAIN SHAFT ANDINCLUDING A ROTOR ROTATABLE WITH SAID MAIN SHAFT; DRIVING MEANSROTATABLE FROM SAID TRANSMISSION MEANS; FIRST RESILIENT MEANS ROTATABLYDRIVEN AT ONE END THEREOF IN RESPONSE TO ROTATION OF SAID DRIVING MEANS;TORQUE TRANSFER MEANS AND MEANS FOR ROTATABLY DRIVING SAME AT ONE ENDTHEREOF IN RESPONSE TO ROTATION OF THE OTHER END OF SAID FIRST RESILIENTMEANS; CLUTCH MEANS FIXED FOR ROTATION WITH SAID MAIN SHAFT AND HAVING ASLEEVE PORTION THEREOF IN TELESCOPED RESILIENT WITH, AND LOCATED CLOSELYADJACENT, SAID FIRST RESILIENT MEANS; AND DISCONNECTIBLE ENGAGING MEANSACTUATABLE TO COOPERATE WITH THE OTHER END OF SAID TORQUE TRANSFER MEANSFOR CONNECTING SAME TO SAID CLUTCH MEANS;